windows share file not able open at same time in multiple system in ubutnu with libre office

hi,

We have windows file and print server, we installed ubuntu 12.04 with libre office 4.4.

Found following problem:
i am not able to access one/same excel file in multiple system at a same time.

how to fullfill my requirement, whoever access the first file need to get read write permission and second user should have read only permission